Printing telegraph apparatus



:51H32 229 'lm/m.

A, E: THMFSGN ET lialim PRINTING TELEGIUMI APPARATUS Filed Di-DC. 29, .1937l 23 24 .2f 25 318 27 29 L- Y M mill n 24 2@ 2 26 27 82 29 g [Q4 SMU L] Egmm 2% i940.` A. E. THQMPSQN m M;

PRINTING TELEGRAFH APPARATUS Filed Dec. 29, 1937 Shwts-Shaet 2 15m/5a 'wma Sept, 24, 1940. A. E. THOMPSON m- AL 2,215,803

PRINTING TELEGRAPH APPARATUS Filed Dec. 29, 1937 4 Sheets-Sheet 3 SeFf- 24, 194@ A. E; THOMPSON m AL 11S PRINTING TELEGRAFH APPARATUS Filed Dec. 29, 1937 4 Sheets-Sham 4 Patented Sept. 24, 1940 UNITED Alfred Edward Thompson and Reginald Dennis Salmon,Croydon, England, assignors to Creed v and Company Limited, Croydon,` Surrey, England `Ampliacion December 429, 1937, serial No. 182,200 In Great Britain January 12, 1937 18 Claims.

This invention relates to a type printingtelegraph receiver of the step by step type.

According to one featureof the invention We provide such a receiver in which the 4type wheel is driven and the printing hammer actuated from a driving shaft rotated by a source of power through a coiled spring.

The actuations ofthe printing hammer may be controlled by the movement of the type wheel shaft in such manner that the hammer is actu-` ated when this shaft is at rest for longer than a predetermined time.

The nature of the inventonwill be better understood from the following description of one embodiment thereof taken Kin conjunction with the accompanying drawings in which:

Fig. 1 is a plan View with some parts shown in section; p

Fig. 2 is a front elevation partly in section with certain parts omitted;

Fig. 3 is a side elevation from the left of Fig. 2;

Figs. 3a. and 3h showdetails of Fig. 3;

Fig. 4 is a section on the line B--B in Fig.,2;

Fig. 5 is a section on the.A line C-C or on the line D-D of Fig. 4; p

Figs.` 6 and 7 show the printing hammer mechanism;

Figs. 8 and 9 show details of the synchronising mechanism for moving the type wheel into a predetermined position; p

Figs.*10, 11,12 and 13 show detailslof a mechanism for indicating the tension in the coiled spring through which the apparatus is driven.

The embodiment illustrated in the drawings is driven from a shaft 2 to which is axed a handle I so that the shaft 2 may be turned by hand, but it is to be understood that this shaft 2 may be driven by an electric motor. The shaft 2 drives, `by means of a worm wheel 4 fixed thereon a gear wheel 3 mounted upon a drum 5. To the inner circumference of drum 5 is fixed one end of a coiled spring G the other end of which is attached to a shaft 1 mounted centrally of the drum 5. The shaft 1 is thus driven from the shaft 2 through tension applied to the coil spring 6.

Keyed to shaft 1 is an arm 20 carrying a planet wheel 16a which meshes with an inner sun wheel 15a, carried on a sleeve I9 Within which shaft 1 is freely rotatable, and anrouter sun wheel 14a. The latter is in the form of a disc having teeth on its inner circumference. It is carried by a drum 2| mounted on a sleeve 22 about shaft 1. Attached todrum 2l is a gear wheel' 23 which meshes with a gear wheel 24 fixed on a shaft 25. On the shaft25 is a gear wheel 26meshing with a gear 21 on a shaft 23 which also carries an es-` capement wheel 29.` One end of a member 30v tached to thearmature 32 of the receiving magi net. Thus the shaftl tendsto drive the shaft 25 through planet wheel i011, outer sun wheel Ida, drum 2i, gears 23 and `.24, but is normally prevented from doing so by engagement of member 30 with `escapement `2Q and this, through gears 21 and 25 holds shaft 25 stationary. When the armature 3?. `moves from one position to the other in response to a line reversal, the escapes ment 253 is allowed to rotate for a quarter of a revolution and thus allows shaft 25 to rotate. Shaft 25 drives, through an inner sun wheel 10d fixed thereon, planetwheel |05, and outer sun-wheel 105, a shaft |01 on whichare fixed type vvheelsZII-a, and 24h. Planet wheel l05'is` mounted on a sleeve |08 freely rotatable about shaft 25 but is held stationary by Imeans` described later. 4

, The sleeve I9 which carries the inner sun wheel 15o, also` carries a gear wheel` 33, `which meshes with a gear wheel 34 on a shaft 35. 'The shaft 35c`arries at one end a cam wheel 36 for `:actuating the printing hammer and at the other `end a detent cam 31 as shown in Fig. 3. This detent cam is normally held stationary by the engagement therewith of one end of a` lever 38 pivoted at 39. The lever 38 tends tobe drawn out of engagement with wheel 31 by aspring 40 but is held in engagement by the' pressure thereon of a frame 4l pivoted at 42 and held against lever 33 by a spring 43. Slidably mounted in frame 4l is a rod 44 which is attached to a lever 45 pivoted on the same pivot pin 39. The lever 45 tends to be rotated in a clockwise direction in Fig. 3 by aspring 45 but is held by an arm 41 of a three `armed lever, bi1, d8, 49. The arm 41 contacts `with the rod i4 and prevents it from rising.

This three armed lever is 'pivoted at 5|, and a 4 roller 52 carried by arm 48 is held against a cam 53 on shaft 28 by a spring 50. The third arm 49 is connected by a link 54 to a ratchet wheel When the shaft 2B is allowed to rotate on the receipt of impulses, the cam 53 throws the .roller 52 away from it and so moves the lever 41, 4t, Il!! inta clockwisedirection about its pivot. The arm 40 rotates ratchet wheel 55 andthe arm d1 moving to the left in Fig. 3 allows rod 44 to rise in front of the tip ofthe arm 41. The raising of rod 44 allows lever `45, to which it is attached, to move clockwise about its pivot 39,

- with which a watch type escapement pallet E0 engages. Thus whilst the shaft V28 is being allowed to rotate by received impulses the roller 52 cannot descend into the hollow of cam 53. When the shaft 28 cornes to rest, however, the roller 52 moves back into the hollow of cam 53 and the arm 41 in moving ycounterclockwise strikes the rod 44, tilts the frame 4| about its pivot, and so releases the lever 38 from engagement with detent cam 31. The detent cam thus allows shaft 35 to rotate. As soon as lever 38 releases detent cam 31, a roller 6| on the lever 38 comes into engagement with a resetting cam 62 also mounted on shaft 35. This cam 32 moves the lever 38 so that it is moved back into the path of detent cam 31 beyond its normal position. Thus the lever 45 is also rotated so as to withdraw the rod 44 from engagement with the lever` 41, thereby permitting the frame 4| to return to its normal position under the influence of spring 43. The resetting cam 62 finally releases lever 38-so as to permit it to set back against frame 4| while still being held in the path of detent cam 31 at the end of one quarter revolution. Shaft 35 is thus allowed to rotate for a quarter of a revolution only.

V`When shaft 35 rotates, cam 38 (Fig. 6) thereon, which engages a projection 64 on the underside of a lever 1E)V strikes this lever upwards. Lever 10 is secured to a lever 63 on the same lpivot and lever 53 is accordingly raised with it. Pivoted to lever 63 at 1| are two printing hammers 12 carrying two resilient pads 13 (of which one only is shown) which project into an aperture 14 in lever 63. The paper strip passes under a curved guide 68 over aperture 14 and between feed rollers l|58 and 69. The guide 66 is providedwith a slot through which one of the pads 13 can press the paper strip against one of thetype wheels 24a or 24h when the lever 63 is jerkedupwards by cam 38. Below the printing hammers 12 is a frame |2| running on Aa pin |22 and arranged so as to engage with one or other of the two printing hammers. The frame is moved endways under the action of a three-armed lever |23, one arm of which engages with the frame |2| and the other two arms of which cooperate with arms 16 and 11 (Fig. 2) on the typewheel spindle |01. The arrangement is such that when the printing hammer frame 63 is thrown upwards under the action of cam 35, one of the two printing hammers 12 is held by the frame |2| so as to strike the paper against the typewheel, whereas the other printlng hammer 12, which is not held, yields under the action of the interposing guard 65. If one of the arms 18 or 11 engages with the three-armed lever |23, the frame 2| will be moved endways; arm 16 thus causes the frame to move in one direction while arm 11 causes the frame to move in the other direction. These arms 15 and 11 are fixed to the type wheel shaft 25 in such manner that i-rnpulsesjrepresenting the figure and let- -ter shifts respectively place one or the other of 'these cams to engage the lever 15 and move it and the guide 66 so that the slot in this guide comes below the appropriate type wheel.

The lever 83 carries a pawl 18 engaging a paper feed ratchet wheel 19, and on the return of lever E3, wheel 1 9 is rotated by one tooth to feed the paper 'strip-forward. A retaining pawl 88 prevents return of the ratchet wheel 19.

In order to give an indication to the person turning the handle I of the tension being applied to the spring 6, a. gear wheel 3 is attached to the drum 5 and drives through an idler gear 9 a gear wheel |0 yon a shaft Gear wheel I2 on shaft meshesV withv a gear I3 mounted to rotate freely about shaft 1. Attached to gear I3 is an outer sun wheel 4, similar to sun wheel 4a. A planet wheel I6 meshes between outer sun wheel I4 and inner sun wheel l5 secured to shaft 1. Planet wheel |6 is carried by a worm wheel I8 which rotates freely about shaft 1. Worm wheel v| 8 meshes with a gear 84 on a shaft 82 which carries an indicator nger 8| moving over a scale 83. It will be seen that finger 8| only moves when there is relative movement between the inner sun wheel |5 driven by shaft 1 and outer sun wheel 14 driven in reverse direction by the drum 5. If the person turning the handle turns at such a rate that he keeps the nger 8| between two given points of the scale 83, most clearly seen in Fig. 13, he is turning at the correct rate. If a motor is used as the driving power such as shown at |8| in Fig. 13, the movement of nger 8| to a predetermined displacement may be made to open contacts |82 in the motor circuit. In this way the motor can be caused to run only when finger 8| is maintained below a predetermined point on scale 83, so that a substantially constant tension on the spring may be maintained.

Since in a step by step printer an error in the selection of one character on the type wheel leads to all subsequent characters being wrongly printed, it is necessary to provide some means for moving the type wheel into a predetermined initial position.

According to a feature of this invention the receipt of a continuous series of a greater number of impulses than that required to rotate the type wheel through a complete revolution causes the stoppageV of the type wheel in a predetermined position.

As previously stated the planet wheel |05 forming part of the sun and planet gearing through which the type wheels 24a and 24h are driven from shaft25, is mounted on a sleeve |08 freely rotatable about shaft 25. Fixed to the sleeve |08 is a toothed disc |00, Fig. 9, which is held stationary by the engagement therewith of a detent |09 mounted on a lever H8. The lever H0 is fixed to a lever held in position by a spring ||2j so that detent |09 is between two teeth of wheel |00. Mounted on shaft |01 is a gear wheel 86, which meshes with a larger gear wheel 85, Fig. 8, to which is fixed a gear wheel 81 mesh- -ing with a toothed segment 88, which rotates about an axis `||3 mounted on a lever 98. Attached to lever is a second lever 9| pivoted on the same pivot 4 and lever 9| carries a roller 93 and is under the influence of a` spring 92 which holds roller 93 against a cam 94 on the shaft 35.

vWhen the shaft |01 is rotated gear 85 drives, through gears 85 and 81, the segment 88 in a clockwise direction in Fig. 8; Each time that shaft is allowed `to rotate through a quarter of a revolution to actuate the printing lever, roller S3 is thrown away from cam 94 and segment 38 is removed from engagement with gear wheel 8l. It is thus returned to initial position by spring t9.

If, however, a greater number of impulses than is required to .rotate the type Wheel through one revolution is received, the segment 88 is rotated until a pin M5 thereon engages a lever IDI-i, turns it in a counterclockwis'e direction and disengages it from a lever |02. Lever |02 then `turns until a nose H4 thereon engages a disc |33 (Figs. 1 and 9), fixed to the shaft |01. The circumference of the disc |03 is formed with a notch I l corresponding to a predetermined position of the type wheels 24a and 24h. As the shaft lill continues to rotate the notch I I1 comes opposite the nose H of lever |02 and the lever falls into the notch under the influence of spring HB. The lever |02 in turning moves lever I|| to remove the detent |09 from Wheel |00. The type wheel shaft is held stationary, and the further rotation of shaft 25 `simply results in idle rotation of the planet wheel |05 and toothed Wheel Illll. As soon as the train of impulses ceases, shaft 35 is allowed to rotate in the manner previously described and roller 93 is thrown away from cam 9G. Segment 38 is disengaged from gear wheel 8l and returns to initial position. The end H9 of lever till engages a projection |20 on lever |02 and removes the nose Il@ from the notch Hl. Lever |2 reengages with latch IUI and allows lever ||I to move so that the detent |09 reengages toothed Wheel |00.

What is claimed is:

l. In a step-by-step telegraph receiver, a type wheel, means including a driving shaft for operating said type wheel, a printing hammer, a printing shaft, a cam on said shaft, means for normally holding said cam against rotation and. releasing it at the end of a train of impulses, and means under the joint control of said cam and driving shaft for actuating said printing hammer.

2. The structure dened in claim 1, and differential gearing connecting said driving shaft with said type wheel and printing shaft.

3. The structure defined in claim 1, a planet wheel rotated by said driving shaft, inner and outer sun wheels meshing with said planet wheel, one of said sun wheels driving said type wheel, and the other the printing shaft.

4. The structure defined in claim l, an escapement wheel on said printing shaft, a detent normally holding said escapement wheel from rotating, `and means operative when the type wheel comes to rest for tripping said detent.

5. In a step-by-step telegraph receiver, a receiving magnet, a shaft, an escapement mechanism controlled by said magnet, means `including said escapement mechanism for controlling the rotation of said shaft through a large fraction of a revolution at each Aactuation of said mechanism by said magnet, a type wheel and means for rotating said type wheel for the distance between two. characters for each said large fraction of a revolution of said shaft.

6. The structure defined in claim 5, a type wheel shaft, a gearing between said shaft and type wheel shaft, and a. source of power normally coupled with said type wheel shaft.

7. In a step-by-step telegraph receiver, a first shaft, means for rotating it, a second shaft, a train of gears comprising an intermediate gear and connecting said shafts, an escapement mechanism normally holding said second shaft against rotation a receiving `magnet controlling said mechanism, and a type wheel controlled by said intermediate gear.

8. In` a step-by-step telegraph receiver, a source of power,` a first shaft rotated by said source of power, a second shaft, means including a coiled spring for rotating said second shaft under the control of said first shaft, a differential gear comprising gears driven respectively by said first and second shafts, and also an additional gear for controlling the tension of said coiled spring.

9. A step-by-step telegraph receiver as defined in claim 8, further comprising a third shaft, a cam pointer attached thereto, means controlled by said additional gearing for rotating said third shaft, a circuit for operating said source of power, and means in said circuit controlled by said cam for controlling operation of said power source.

10. In a step-by-step printing telegraph receiver, a type wheel, a Wheel rotating with said type wheel, a lever, means for causing said lever rapidly to move away from said wheel and relatively slowly to return towards said wheel, a

printing hammer, and means controlled by said lever during its relatively slow movement for automatically actuating said printing hammer.

11. The device dened in claim 10, and in which a rotatable shaft is provided for actuating said printing hammer, and a detent restraining movement of said shaft tripped by said lever during its relatively slow return movement.

l2. The device defined in claim lo, a ratchet wheel actuated `by said lever, a pawl under which said ratchet wheel rides when the lever is moved in one direction and which is engaged by the ratchet wheel When the lever is moved in the opposite direction, and a gear wheel rotated by said ratchet wheel when it engages said pawl.

13. In a step-by-step telegraph receiver, a lever, a type wheel, means for rotating said type wheel step-by-step, means for moving said lever rapidly in one direction on each step of rotation of said type wheel, means for moving said member, means for releasing said trip member during the rst mentioned ratchet movement of said lever and engaged by said lever during its second mentioned relatively slow movement, and means for actuating the printing hammer by said trip member.

15. The device according to claim 13 in which the printing hammer is actuated by means of a cam, a trip member, means for releasing said trip member during the first mentioned rapid movement of the lever, means for engaging said trip member by the lever during the second mentioned relatively slow movement, and a detent controlled by said trip member for releasing said cam for a limited motion.

16. In a step-by-step telegraph receiver, two type wheels, a printing hammer, and means controlled by said printing hammer operable in certain positions of each type wheel for` moving the other type wheel into printing position.

17. In a step-by-step telegraph receiver, means for receiving trains of impulses, a type wheel,

and means responsive to a train of more than a predetermined number of impulses for posi tioning the type wheel in a predetermined position.

18. The device dened in claim 17, a differential gearing for driving said type wheel, means responsive to the receipt of more than the 4predetermined number of impulses for holding said type Wheel stationary, and means for rotating said gear idly in response to impulses in excess of said predetermined number.

ALFRED EDWARD THOMPSON. REGINALD DENNIS SALMON. 

